Because M. Mionnet used very few sources for his books (Sestini being cited for most coins), Friedländer, in this work, adds additional sources and citations for a large number of coins. It can be used less of a reference work than Mionnet itself, as detailled coin descriptions are not given. The book also contains some corrections and additional inscriptions and coin reverse types, the use of which continued to the next ruler. So in that respect it can be useful, though, as I say, Mionnet remains the primary reference work.